I think the inclusion of R2-D2 is actually pretty important to this set.
Why? I'd rather see a new Ewok or a Rebel Commando given the potential for a different scene.
First, from a pure sales perspective? Han and R2 are going to help sell this set to the casual buyer. Mom's and Dad's who are buying for their kids are going to more readily recognize Han & R2.
As for R2's importance to this setting as a whole? Who was trying to break into the Endor bunker? It was R2 with Han protecting him. That gives the set a sense of story, instead of just "good guys vs bad guys".
We know we're getting more Ewoks next year. Plus the three in the comic packs. As for an Endor Rebel? Do you really think that Hasbro would package a really good Endor Rebel into a battle pack? I don't. I think they would save a new figure like that for the Basic Figure line. They'd probably make more money that way since army builders would be more inclined to buy multiples of a basic figure than multiples of battle packs with figures that aren't as well articulated.
I couldn't disagree more. I'm a dad and have plenty of friends with kids who are into Star Wars. I don't know of any of them that would buy this for their kids based on Han and R2 being recognizable. If anything, kids will tell the parents which sets they want and most kids probably have one of a gazillion versions of Han or R2 already. When I was young, troopers were always the coolest figs after you had your 2nd, 3rd, 4th version of the main characters and I'd bet that most kids feel the same way today.
I think Ewoks, more imperials, a rebel diguised as a Biker Scout - all of these not only align with the "scene" in the set, but would be much more appealing to kids and collectors alike. Heck, I'd rather have a wounded Leia than another R2 - that scene was better and more meaningful than R2 getting fried. Repainted ewoks or even the same Ewoks from the Target Ultimate Battle Pack would be more appealing and probably even cheaper to include than a "new" R2.
Don't agree with your comment on Army builders either. If you put four army building figures into a battle pack, I think they would sell like hot cakes. Why would an army builder prefer to buy single carded figures at $8 versis BP figures at $5? The problem is that most BPs don't include Army building figures or force you to buy extras of additional figures you don't want. Not sure what Battle Pack surplus looks like where you're located, but I'm seeing a ton of leftover Hoth Recon Patrol sets (scene/main character driven) and very few Speeder Bike Recon or Hoth Speeder Bike Patrols - both of which are potential army builders and happen to come with two fewer figures for the same price.